A decision by Attorney General Cuomo to steer of the growing battle over how much state judges are paid is costing taxpayers.

Mr. Cuomo’s office, which defends the state and its officials against lawsuits, has declined to represent the governor, the Assembly speaker, and the Senate majority leader against Chief Judge Judith Kaye’s allegation that legislators are violating the state constitution by refusing, year after year, to raise the basic salary for state judges above its current level, $136,700.

Mr. Cuomo could be avoiding the dispute because he is seeking to be insulated from the ill will that some state judges are directing toward the legislators who are keeping their pay down, observers said.

The defendants in the case thus have had to turn to private lawyers in Manhattan, who will be paid for by the state, to defend against the suit. Majority Leader Joseph Bruno’s attorney, David Lewis of the firm Lewis & Fiore, said he would bill less than his usual $400 an hour, but said the rate hasn’t yet been decided. The attorney who is representing Governor Paterson and Speaker Sheldon Silver in the dispute, Richard Dolan of Schlam Stone & Dolan LLP, will bill $350 an hour, a spokesman for Mr. Paterson, Errol Cockfield, wrote in an e-mail message.

A spokesman for Mr. Cuomo said the decision to force Messrs. Paterson, Bruno, and Silver to find their own attorneys was based on conflicts of interest that taking the case might have presented to the attorney general’s office, which regularly represents each of the parties in the suit, including the state judiciary, in other litigation.

“The potential conflicts are obvious, and the most rational, reasonable move is for us not to represent any of the parties,” a spokesman for Mr. Cuomo, John Milgrim, said in a statement.

One conflict that might have arisen had Mr. Cuomo taken the case stems from Mr. Bruno’s defense. He is expected to argue that any grievances the judges have would better be addressed to Mr. Silver than to him. The Senate last year approved a bill that would have given judges the pay raise they sought; the Assembly did not pass a similar bill.

A legal ethicist at Fordham University School of Law said Mr. Cuomo’s decision not to defend the case may have less to do with conflicts with Messrs. Bruno and Silver than a concern that his office would, by taking the case, be making enemies of the state judges before whom most of the attorney general’s business occurs.

“It’s in the state’s interest for the attorney general not to offend the judiciary — not so much because of the attorney general’s feelings about not being loved, but because it doesn’t help his clients in future cases,” the legal ethicist, Bruce Green, said.

The attorney general, Mr. Green said, could be concerned that defending Messrs. Paterson, Bruno, and Silver against the judges in the pay raise litigation “will affect how judges make decisions vis a vis his clients in future cases.”

Mr. Milgrim declined to respond to this claim.

Mr. Lewis, the lawyer for Mr. Bruno, once represented a former Panamanian leader, General Manuel Noriega, on drug-trafficking charges, and more recently represented the state Senate in its investigation of the so-called Troopergate scandal.

Mr. Lewis said he believes he was hired to defend Mr. Bruno in the judicial pay dispute because of his role in a precedent-setting case on the state constitution’s speech and debate clause. That clause prevents legislators from being sued or deposed “for any speech or debate” in the Legislature. Messrs. Bruno and Silver are likely to argue that the clause precludes them from being sued over the Legislature’s decision not to pass legislation enacting a pay raise.

In a telephone interview, Mr. Lewis criticized what he saw as the legal tactics of Chief Judge Kaye, whose civil complaint hints she will seek to have Messrs. Bruno and Silver testify about what income they receive from outside jobs as, in Mr. Bruno’s case, a consultant and, in Mr. Silver’s case, as a lawyer associated with the law firm Weitz & Luxenberg.

For the judges to push to have the legislators’ “personal information outed to the world” because the judges did not receive a pay raise, Mr. Lewis said, “sounds like in another venue it would be blackmail.”

Mr. Lewis suggested that he will, in return, seek Chief Judge Kaye’s testimony on her own finances.

“Tactically, how does that not happen?” he asked.

The lawsuit, which is filed on behalf of Chief Judge Kaye, is being brought pro bono by a partner at Wachtell, Lipton, Rosen & Katz, Bernard Nussbaum.